用所给动词的正确形式填空
1. We know the earth  _______ (travel) around the sun.
2. Can you see the students _______ (plant) trees on the hill now?
3. ---Where’s your father? ---He _______(clean) the car behind the house.
4. I am sure she ________ (be) a very good teacher in a few years.
5. He wanted my help. So I stopped ________ (help) him.
6. Was Jane very busy ________ (plan) a boat trip with you last night?
7. It is very important ________ (not give) your goldfish too much food.
8. The boss usually makes his workers ________ (work) for twelve hours every day.
9. David ________ (fall) off the tree and hurt his legs a moment ago.
10. Millie, __________(not frighten) the dog, or it will bark at you.